Pulverizer



Augi- 1944- E. J. DONDLINGER 2,355,784

PULVERIZER.

Filed Jan. 7, 1942 2 Sheets-Sheet 1 Aug. 15, 1944. E. J. DONDLINGER 5PULVERIZER Filed Jan. 7, 1942 2 Sheets-Sheet 2 INVENTOR.

Patented 'Aug. 15, 1944 UNITED STATES PATENT OFFICE PULVERIZER Eugene J.Dondlinger, Chicago, 111. Application January 7, 1942, Serial No.425,833

v 10 Claims. (01. 83-11) Thi invention relates to pulverizers of thetype suitable for pulverizing coal to be supplied in comminuted form toheating apparatus such as a furnace or boiler, or for use in brickkilns, core ovens or steam heating equipment.

One object of the invention is to provide an improved pulverizer inwhich th motor driven shaft is positioned vertically and has a blast fancombined with and built into the rotor of the pulverizing mechanismwhereby the apparatus is rendered unusually compact and efllcient.

Another object of the invention is to provide a pulverizer of thehammermill type combined with suction apparatus which creates a flow ofair for carrying of! the finely divided material and in which such airis led in a tortuous ath, which includes vanes or baifies, some of whichare rotated with the pulverizlng mechanism and serve a to throw out ofthe air stream the coarser particles which require furtherpulverization.

It is also an object of the invention to provide a pulverizing apparatushaving a comparatively simple casing structure adapted to be readilyseparated to give access to the pulverizing mechanism, and particularlyto the liners which may require occasional renewal as a result of thewear to which they are subjected.

In general, it is'the object of the invention to provide an improvedpulverizer of the type indicated, which shall be simple and economicalin construction and eflicient in operation. Other objects and advantageswill appear from the following description taken in conjunction with theaccompanying drawings in which:

Figure 1 is a vertical sectional view taken substantially at the axis ofthe main shaft of the pulverizing mechanism and showing a machineembodying this invention.

Figure 2 is a horizontal section taken as indicated at line 2-2 onFigure 1.

Figure 3 is a horizontal section taken as indicated at line 33 onFig-ure1 showing the auxiliary air fan or blower.

The pulverizer shown inthe drawings includes a base l adapted to beanchored to the floor, as by bolts 2, and formed to support the lowersection 3 of the casing. This lower section houses the pulverizermechanism and is surmounted by an upper section 4 containing a blowerfor supplying auxiliary air when the pulverizer is employed inconnection with heating apparatus, so that the powdered coal deliveredby the pulverizer requires additional air for complete combustion. Thcasing 4 supports a driving motor 5 and encloses the drive pulley 6, thedrive belt 1 and the driven pulley 8, which is secured to the upper endof the vertical shaft 9 disposed axially within the :asing. Rollerbearings are shown at I for the lower end of the shaft, and ballbearings are provided at I l for the upper end of the shaft. Thesebearings are protected from the dust and gritof the pulverized materialby suitable packing at l2, adjacent the lower hearing "I, and at l3,just below the upper bearings I I.

The pulverizing mechanism is of the hammermill type, including a rotorsecured to the shaft 9 and comprising an upper plate 14 and a lowerplate 15 between which the hammers l6 are carried on pivot pins IT. Therotor also includes a hollow hub structure composed of an inner sleeveI8 which fits the shaft 9 and is suitably keyed thereto, and an outersleeve IS with an annular .wall 2!! connecting said sleeves at theirupper ends. The space between the sleeves l8 and I9 is an annularchamber, open at the lower end except for a limited-number of spokes 2|extending substantially in the plane of the lower plate l5. This loweropen end of the rotor hub communicates directly with an air intakechamber 22 which is formed between a horizontalpartition 23 and thehorizontal bottom wall 24 of the pulverizing chamber. Said wall 24 has acentral opening 25 directly opposite the lower open end of the rotorhub, and at one side the chamber 22 is provided with an air intake port26 and an adjustable gate or cover 21 which is slidably shiftable tovary the effective area of the port and the resulting rate of airsupply. The outer sleeve 19 or the rotor hub has a. plurality of outletopenings 28 disposed opposite the intervals between the hammers l6, andin these intervals there are secured between the upper plate I4 andlower plate l5 a plurality of fan blades 28 so that rotation of therotor member operates to induce a flow of air from the port 26 throughthe chamber 22 into the hollow hub of the rotor and outwardly from theports or openings 28 therein, and the centrifugal force of the rotationimparted to the air by blades 29 discharges the air forcibly past thehammers l6 and toward the impact lining 30 with which the hammerscooperate.

The pulverizlng chamber 3|, disposed between the bottom wall 24 and thetop wall 32, communicates at one side with the feed tube 33, having afeed conveyor screw 34 therein, as shown in Figure 2, and the lining 30is interrupted at 35 to provide an opening through which the materialadvanced by the screw 34 may be picked up by the hammers I 8 as theyrevolve past the opening 35. This material is thus carried around in theof said top wall.

pulverizing chamber and thrown against the lining 30 by centrifugalforce acquired in its rotation, and is broken up and crushed by theimpact of the hammers IS in this action. The finer particles are pickedup by the air stream which travels in the general direction of thearrows in Figure 1 and escapes upwardly through an outlet port 36 in thetop wall 32 of the pulverizing chamber and adjacent the central portionthereof.

The outlet 36 leads directly into the fan chamber 31, which encloses fanblades 38 secured to the shaft 9 and rotating therewith to operate as acentrifugal blower. This blower includes an air intake passage 39 havingan adjustable intake valve or gate 40, said passage being disposedbetween the outer wall of the upper casing section 4 and the wall 4| ofthe fan chamber 31, and being upwardly open for communication with aspace 42 between the partition 43 of the casing section 4 and the topwall 44 of the fan chamber.

The latter wall 44 has a central opening 45 by which the air is admittedto the fan chamber, whereupon it is picked up by the fan blades andthrown by centrifugal force through the outlet passage 46. This passagemay be coupled to any suitable conduit leading to the combustionapparatus, such as a furnace or kiln in which the mixture or air andfinely pulverized fuel is to be burned.

In the pulverizing chamber the air stream will at first pick up some ofthe coarser particles of coal which are not sufliciently reduced forsatisfactory combustion, and to prevent these particles from passing outof the chamber 3| I provide a system of baiiies tending to arrest themovement of the coarse fuel particles without interfering with thecontinued flow'of air. Stationary bafiles 41 are disposed insubstantially radial planes, depending from the top wall 32 of thepulverizing chamber, being in the form of plates bolted to suitable lugs48 on the under side Additional baflies or blades 49 are secured insubstantially radial position upstanding from the upper plate l4 of therotor, and, as shown, the lower inner corners of the baflle plates 41are notched at 50 to provide clearance for the passage of the upperouter corners of the baffles 49 as they rotate. It may be understoodthat the fixed baffles 41 are not necessarily disposed in strictlyradial planes, and that experiment may determine the more effectiveangles for these plates, slightly away from the radial position, so thatthey shall function to arrest the swirling movement of the coalparticles incident to the rotation imparted to them by the hammers I6and by the general direction of the air stream through the pulverizingchamber. With their velocity thus reduced the coarser particles willtend to fall by gravity back to the pulverizing zone where they will befurther treated and comminuted by the action of the hammers against thecooperating lining 30. The finer particles, however, will travel in adust cloud along with the air stream past the surfaces of the baffies4'! toward the outlet 36. If some of the coarser particles are carriedpast the baflie plates 47 they will encounter the rotating blades 43,and the centrifugal force thus imparted will operate to throw theparticles clear of the air.

draw airthrough the intake 45 in the upper wall I of its housing butwill also exert a pull on the air entering by way of the opening 36 inthe wall 32.

The lining 30 of the pulverizing chamber may be made in sections,secured in place by screws or bolts 5| extending into or through thewall 3 of the lower casing section. The inner surfaces of these sectionswill be formed with vertically extending corrugations 30, as seen inFigure 2, and when these surfaces become worn the sections can bereadily replaced upon removing the upper portion of the casing,including the wall 4 and the motor 5 superimposed thereon. As shown inFigure 2, the feed tube 33 includes an extension 33 beyond the opening35 through which the coal normally enters the pulverizing chamber. Thisextension or pocket will tend to fill with coal as it is fed along thetube by the screw 34, but any large, hard lumps of foreign material,such as tramp iron, will be driven into the body of coal in the pocket33 by the impact of the hammers IS in their travel past the opening 35,and the accumulation of such material can be removed from the pocket atintervals.

With the structure as described, the air stream delivered by the fanblades 29 of the rotor mingles immediately with the material undertreatment by the hammers l6, and is thus disposed most fflciently forentraining the fine particles which are ready for delivery to thecombustion apparatus; --and, at the same time, the baflie plates 41 andbattle blades 49 are positioned to act immediately upon the materialpicked up in the air stream so as to eliminate therefrom the coarserparticles which should not be transferred to the combustion zone withoutfurther pulverization. To further insure elimination of the coarsermaterial the outlet 36 is surroundedbv a depending baiile ring 5| whichdeflects the air stream downward to a slight extent in the vicinity ofthe rotating vanes 49. As indicated in Figure 1, the incoming air streampassing upwardly through the central opening 25 in the bottom wall 24 ofthe pulverizing chamber may be allowed to divide so that a portion ofthe air flows outwardly under the lower flange IE only a short distanceabove the bottom wall and toward the peripheral lining 30. This airsweeps across any accumulation of coal lying on the bottom wall 24 so asto pick up all the finer material therefrom and carryit along upwardlytoward the discharge opening at 36, thus preventing the undueaccumulation of material in the bottom of the chamber where it mightinterfere with rotation of the rotor and with the free action of thehammers l6.

While there is shown and described herein certain specific structureembodying the invention, it will be manifest to those skilled in the artthat various modifications and rearrangements of the parts may be madewithout departing from the spirit and scope of the invention, and thatthe same is not limited to the particular form herein shown anddescribed, except in so far as indicated by the appended claims.

I claim as my invention:

1. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation therein, the combination of a pulverizingchamber, a rotor in said chamber including vertically spaced horizontalflanges with an inlet for air only leading to the space between saidflanges, impact members swingably mounted in said space between theflanges, and fan blades disposed at intervals verized and an opening inits upper wall for around the shaft in said space, together with aseparate passage through which material to be pulverized is admitted tothe chamber.

2. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation' therein,

for admixture with material pulverized by the impact members, togetherwith-means delivering -material to be pulverized directly into theperipheral portion of the chamber in the path of said, impact members.

3. In a ulverizer which includes a casing and a vertical shaft journaledfor rotation therein, the combination of a pulverizing chamber, a rotorin said chamber comprising a hollow hub on the shaft with an upper plateand a lower plate extending horizontally therefrom in vertically i saidstream.

spaced relation, said hub being closed at its upper end and open at itslower end, the interior of the hub opening into the space between saidplates, impact members pivotally carried between said plates andextending outwardly beyond them, and fan blades disposed at intervalsaround the shaft in the space between the plates inducing a flow of aironly into the openend of said hub and outwardly between the plates whenthe shaft rotates, together with means delivering material to bepulverized directly into the outer portion of said chamber in the pathof said impact members.

4. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation therein, the combination of a pulverizingchamber, a rotor in said chamber comprising a hollow hub on the shaftwith an upper plate and a lower plate extending horizontally therefromin vertically spaced relation, said hub being closed at its upper endand open at its lower end, the interior of the hub opening intothe spacebetween said plates, impact members pivotally carried between saidplates and extending outwardly beyond them, and fan blades disposed atintervals around the shaft in the space between the plates inducing aflow of air only into the open end of said hub and out- -wardly betweenthe plates when the shaft rotates, said pulverizing chamber having anopening through which material to be pulverized is admitted directly tothe outer portion of the chamber in the path of the impact members andhaving a centrally disposed opening in its upper wall for discharge ofair and any pulverized material entrained thereby.

5. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation therein,-

the combination of a pulverizing chamber, a rotor in said chamberincluding vertically spaced flanges with an inlet for air only leadingto the space between said flanges, impact members mounted in said spacebetween the flanges and traversing the outer portion of the chamber, andmeans operated by rotation of the shaft and producing an air blastoutwardly between the flanges, said chamber having an opening in itsperipheral portion admitting material to be puldischarge of air andmaterial treated therein, together with approximately radial baiilesdepending from said upper wall radially beyond the discharge opening andin the path of the air stream toward the discharge opening for arrestingthe coarser, solid particles and causing them to drop back into thepulverizing zone.

, 6. In a pulverizer which includes a casing and a vertical shaftiournaled for rotation therein, the combination of a pulverizingchamber, a rotor in said chamberincluding vertically spaced flanges withan inlet for air only leading to the space between said flanges, impactmembers mounted in said space between the flanges, and means operated byrotation of the shaft and producing an air blast outwardly between theflanges, said chamber having an inlet for material to be pulverized andhaving a centrally disposed opening in its upper wall for discharge ofair and material treated thereby, together with baffles supportedfixedly in the pulverizing chamber above the impact members radiallybeyond the discharge opening and in the path of the air stream flowingtoward said discharge opening for removing the coarser particles from 7.In a pulverizer which includes a casing and a vertical shaft J'ournaledfor rotation therein, the combination of a pulverizing chamber, a rotorin said chamber including vertically spaced flanges with an air inletleading to the space between said, flanges, impact-members mounted insaid space between the flanges, and means operated by rotation of theshaft and producing an air blast outwardly between the flanges, saidchamber'having an opening in its upper wall for discharge of air andmaterial treated thereby, together with approximately radial baiilesdepending from said upper wall radially beyond the discharge opening andin the path of the air stream for arresting the coarser, solid particlesand causing them to drop back into the pulverizing zone,'and radiallydisposed vanes carried by the rotor in a path closely adjacent saidbaflles to fling said .particles outwardly away from the dischargeopening as they fall out of the air stream.

8. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation therein, the combination of a pulverizingchamber, a rotor in said chamber including vertically spaced flangeswith an inlet for air only leading to said space between the flanges,impact members mounted in said space between the flanges, and meansoperated by rotation of the shaft and producing an air blast outwardlybetween the flanges, said chamber having an inlet for material to bepulverized and an opening in its upper wall for discharge of air andmaterial treated thereby, together with a bafiie ring depending from theupper wall of the pulverizing chamber around its discharge opening, andradially disposed vanes carried by the upper side of the rotor directlybelow said ring.

9. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation therein, the combination of a pulverizingchamber, a rotor in said chamber including vertically spaced flangeswith an air inlet leading to the space between said flanges, impactmembers mounted in said space between the flanges, and means operated byrotation of the shaft and producing an air blast outwardly between theflanges, said chamber having an opening in its upper wall for dischargeof air and material treated thereby, together with approximately radialbaflles depending from said upper wall radially beyond the dischargeopening and in the path of the air stream for arresting the coarser,solid particles and causing them to drop back into the pulverizing zone,radially disposed vanes carried by the rotor in a path closely adjacentsaid baffles, and an annular baflle adjacent the discharge opening andabove said vanes.

10. In a pulverizer which includes a casing and a vertical shaftjournaled for rotation therein, the combination of a pulverizing chamberhaving a centrally disposed air inlet in its bottom wall, a rotor insaid chamber including vertically spaced flanges with an air inletleading from the inlet of the chamber to said space, impact memv hersmounted in said space between the flanges, and means operated byrotation of the shaft and producing an air blast outwardly between theflanges, said chamber having an opening in its upper wall for dischargeof air and material treated thereby, together with a blower surmountingthe pulverizing chamber with its fan carried on the shaft of thepulverizer, said discharge opening leading into the fan chamber of theblower, and an air inlet for additional air leading into the fan chamberof the blower with means for varying the capacity .of said inlet atwill.

EUGENE J. DONDLINGER.

